Suffixes are employed indicating the source of authority for a statement. That which is perceived by the sense of hearing, for example, has a suffix for past time and another for present time. When the transaction is in sight another suffix is used. Things which are conjectured from circumstantial evidence, as the building of a fire from the remains of one, have -xolan added to the verb, and the word has the meaning, "they must have built a fire for here are the ashes." Future acts which are contingent on human will or outward circumstances are rendered by the suffix -de. Attempted but unsuccessful acts have xow, an adverb, inserted before the verb, while an act successful after several vain or inefficient trials has -ei suffixed to the verb.4

4Goddard, P.E.n/an/an/an/a, "Athapascan," in Boas, , 1: 105–106 (résumé).